This invention relates to a contact lens cleaning and disinfecting system and, more particularly, a contact lens cleaning and disinfecting system which provides cleaning, disinfection and storage in an all-in-one unit.
Contact lenses have become widely used, and advanced lens materials and care products have been introduced years ago. However, proper care still remains an expensive and time consuming process which tends to discourage potential users or causes users not to follow recommended care procedures. Proper contact lens care should include the steps of (1) removing foreign particles, smoke film, and other deposits such as mucous, proteins, and enzymes from the lenses and (2) disinfecting organisms in the deposits and on the lenses to prevent eye infections from their subsequent use. Disinfection is particularly important for the use of "soft" contact lens (hydrophilic) which are able to absorb moisture from cleaning solutions.
The conventional cleaning process includes a daily regime of the lens scrubbing (by manual rubbing) with a soap or detergent, followed by rinsing with water. The use of tap water is not recommended due to the presence of hard minerals in most tap water. Besides being inconvenient, the manual rubbing and handling of the lens during cleaning can cause scratches or microscopic damage to the lens. The lens must then be disinfected, by soaking it in a chemical solution and/or by heating for as long as six hours or overnight. The disinfection step is long, and the chemical solution usually contains detergents, enzyme removers, preservatives, and other chemicals which can be absorbed into the lens and become very irritating to the eyes and membranes. Heat disinfection is generally not effective for cleaning deposits from the lens, but rather tend to bake mineral deposits onto the lens surface. Also, repeated heating of the lens for the disinfection step eventually causes physical degradation of the lens material.
Examples of prior attempts to provide an improved system for cleaning and/or disinfecting contact lens are described in many U.S. patents. These patents have focused primarily on improvements to the chemical system used for disinfecting the lens or on the manner in which the contact lens is exposed to the chemical system.
For example, the system disclosed in U.S. Pat. No. 5,320,806 (Dziabo et al.) employs a liquid electrolyte containing a chlorine dioxide precursor. By passing electric current through the liquid electrolyte a disinfectant of chlorine dioxide is formed. Chlorine dioxiode is described in the patent as being less irritating to the eyes than conventional chemical solutions.
The system disclosed in U.S. Pat. No. 5,082,558 (Burris) employs an ozone generator and a pumping system that mixes the generated ozone with a purifying liquid and brings them into contact with the contact lens.
The system disclosed in U.S. Pat. No. 4,852,592 (DiGangi et al.) employs a plurality of disposable solution containers for sequential cleaning cycles using daily cleaning solution, enzymatic solution, disinfecting solution and saline/neutralizing solution. A timing cycle module provides sequential fluid supply both to and from a cleaning chamber (where the contact lens are positioned) and controls agitation of the lens.
The system disclosed in U.S. Pat. No. 4,36,536 (Leopardi) employs carbon dioxide at high pressure for a period of at least twenty (20) minutes to affect sterilization.
The above systems are still too complex, generally expensive to manufacture and have not achieved commercial success. Moreover, they all employ solutions that can be irritating to the eyes and membranes since they inherently involve the use of disinfecting chemical processes. Accordingly, there is still a need for an improved system for cleaning and disinfecting contact lens, particularly one that is an all-in-one unit.
In light of the above, it would be desirable to be able to provide a contact lens cleaning and disinfecting system which does not utilize irritating chemicals, preservatives, detergents, or enzyme removers.
It would also be desirable to be able to provide a contact lens cleaning and disinfecting system which cleans deposits in a hands-free process from the contact lens in a relatively short time.
It would further be desirable to be able to provide a contact lens cleaning and disinfecting system which can disinfect the lens without the need for a time-consuming heating step or the use of disinfectant chemical solutions.
It would still further be desirable to be able to provide a contact lens cleaning and disinfecting system that is inexpensive to manufacture and easy and convenient for a user to operate.